Tamiya 70188 Mini Motor Gearbox (8-Speed) Kit

Tamiya’s 8-speed mini motor gearbox features a more compact 030-form-factor brushed DC motor driving a single gear train that can be assembled to have one of eight gear ratios: 7.5:1, 9.5:1, 15.7:1, 19.9:1, 32.9:1, 41.8:1, 79.1:1, or 87.8:1.